What should be the cost of increasing your chances an immeasurable amount in regards to obtaining something of unknown value?
This is the question that is at the core of every trade deadline deal. It should be immediately obvious that one cannot get an answer, as there are two unknowns in the equation. But, whether it be based on hunches and gut feelings, made up numbers, or the current set of statistics, guys who are employed in the game, or employed talking about the game, haven't let that little caveat stop them from acting like they can.
If the current set of stats guys don't deal in made up values, how do they answer the unknowable? They make assumptions. The "unknown value" of a playoff win is treated like the chances of obtaining a normal win. The "immeasurable amount" is estimated by delving into all sorts of facts and figures. How likely it will be for player A to face certain situations? How much more likely is player A to be successful in these situations than player B? All of this controlled for line-ups and ballparks and etc.
When it comes to the playoffs this almost can't help but produce the conclusion that trading for someone makes a very small difference, if any at all. The difference between a good player and a great player is measured out in seasons and careers, not the span of 7 games. Luck will dominate such a small time frame. Since this part of the answer seems obvious, they move onto a more long term question. What is the value of the player received likely to be against the value of the players given up? Given the age, career arc, recent statistics, minor league projections, positions in question, etc. etc. they get a picture. Almost always the picture is the same, there is no point in trading a good prospect. The value brought in is almost always going to be less than the average value sent out.
This is a fair answer. But it's an answer to a question that was not asked. If the response was framed as such, "We can't answer the relevant question at hand, no one can, however we can provide this other information which may inform your decision" then it would be fine. However, it doesn't pay to be wishy-washy so there is no framing. This is presented as THE answer.
Of course, it isn't. We've talked ad nauseum regarding the Strasburg shutdown on how you cannot evaluate things that do not happen. History is not going to show that Aroldis Chapman improved the Cubs pen over Adam Warren by whatever the average WAR he is expected to do so by statistics. He's going to improve it by ????? He will perform one way in the set of circumstances he sees. This is going to be a known. Adam Warren will have performed ??? in the ??? set of circumstances he would have seen. This is an unknown. We can estimate what it might be. We can make deals based on these estimates going for deals that were right at the time. But after all is said and done we don't actually know what effect a trade really had, and all we care about are deals that were right in the end, not at the time.
The question of the value of a win is tougher. What is the value of a playoff win? Of a playoff series win? Of a World Series win? Yes, gates can be estimated. Yes, apparel sales can be projected. But what is the psychic value of these things? What would it mean to the city of Chicago, to the legion of those fans, to win a World Series? What is that worth?
A numbers guy might tell you that the best way to improve your chances of that is to make the playoffs as much as you can. What they downplay though is the chances of doing such a thing. The value presented by prospects in the future in itself is FAR more variable than the value presented by a current major leaguer in the current season. But there is a second variability often ignored, the variability of the quality of the entire team when the value of the prospects is expected to come into play. A guy like Chapman is very likely to produce in a certain way this season. The Cubs are very very likely to be in the playoffs this year and to have a good shot at being a favorite. Next year? The year after? It doesn't take long into the future, 3 years?, before things get so hazy for projections to barely be better than guesses. You might want to believe that a well-run team can provide more consistency in future estimates of performance but injuries, free agent signings, and the variability in the other teams you face in your division and conference all come into play. Maikel Franco becomes Mike Schmidt and Aaron Nola becomes Steve Carlton and it doesn't matter if Victor Robles is a solid CF and Reynaldo Lopez is a good #3 exactly as projected. This point is very important : You can't say you are sacrificing the future when you have no idea, really no idea, what the future will bring.
This is a wordy long post to say that if you want the Nats to win this year - maybe you make a trade. It's not a question with a set answer, a clear yes or no, it's an opinion. My opinion is yes. I think a trade will help the team in the pen and in ways we may not be able to measure. That's my opinion.
If instead, you want the Nats to have the most value on their team in the future, then the answer is clearer. You probably don't make a trade. It depends on the actual offers out there but any good prospect, or set of prospects, is very likely to "out-value" whatever you can bring back. However, understand this is not saying "if you want the Nats to win the most games in the future" or "if you want the Nats to have the best chance to win in the playoffs in the future". Those, like the question at the top of the post can't be answered simply. This is only saying "if you want the Nats to have the most value in the future". That's it.
For me, in sports, value without the certainty of winning, is not worth much at all.